As energy is recently increasingly used worldwide, supplementary problems, such as environmental pollution, are frequently generated. In order to solve the problems, eco-friendly alternative energy is being developed worldwide.
Since to change chemical energy now being used all at once is difficult, much research is being carried out in order to improve efficiency of devices that use energy as one option for solving problems, such as environmental pollution and research for economic effects resulting from reduced maintenance costs is also being carried out.
As part of the research, various types of high-efficiency heat exchangers are being proposed in order to improve the heat transfer efficiency of gas devices, such as a boiler for heating and a water heater.
In order to improve the heat exchanger efficiency, a method of increasing a heat transfer area by adding a plurality of heat exchange roots is chiefly used. In this case, there is a problem in that the volume of a heat exchanger is increased. Furthermore, there is a problem in that a loss of water pressure is increased because a channel between a water inlet port and a water outlet port is increased due to the added heat exchange roots.
Furthermore, in a low-efficiency heat exchanger, there is no problem in the generation of condensate water, but in a high-efficiency heat exchanger, there is a problem in that condensate water is generated and the generated condensate water deteriorates heat exchange efficiency.
In particular, a conventional one path condensing heat exchanger is problematic in that volume is increased on the basis of a direction where water flows. Furthermore, a conventional two-path condensing heat exchanger is problematic in that a manufacturing process is complicated because a fluid passage has to be formed by plural times of welding processing and the lifespan of the condensing heat exchanger is reduced due to corrosion.